In the past many attempts have been made to provide a truly dependable emergency fuel supply for internal combustion engines, such as are used in automobiles, trucks, buses, and other road vehicles.
Many of these prior art devices involved the use of an additional fuel tank, such that if the main fuel tank became empty as a result of all of the fuel having been consumed, from the fuel tank having been punctured, or the like, a switchover could be effected either manually or automatically such that a sufficient amount of fuel was provided from the additional fuel tank to the fuel-air mixer of the engine in order to keep the engine running.
It has also been known to provide an additional fuel tank for extended travel requirements or for emergency road use, as well as in other instances to provide a second fuel tank employing a relatively small quantity of premium quality fuel usable for starting an engine. In very cold weather, for example, this premium fuel could be used for starting the engine, with switchover to less expensive fuel being accomplished at such time as the engine has warmed up.
An important shortcoming of all of these earlier systems involved the fact that should the carburetor ice up, the fuel pump fail, the fuel line to the carburetor become clogged, or some other misfortune befall one or more of the principal components of the fuel system, the conventional auxiliary fuel arrangement was unable to overcome the problem, and to keep the engine running.
It was in an effort to overcome the shortcomings of these and other such prior art devices and systems that this invention was evolved.